Move enable extensions define to a build flag.

chrome/browser/supervised_user/supervised_user_service_unittest.cc

Index: chrome/browser/supervised_user/supervised_user_service_unittest.cc
diff --git a/chrome/browser/supervised_user/supervised_user_service_unittest.cc b/chrome/browser/supervised_user/supervised_user_service_unittest.cc
index c17e938a0ee303579de1eacd7ff014191fdff1f5..af98de1259dbe9242504bc6d4e5b3a1c6681e180 100644
--- a/chrome/browser/supervised_user/supervised_user_service_unittest.cc
+++ b/chrome/browser/supervised_user/supervised_user_service_unittest.cc
@@ -38,9 +38,10 @@
 #include "components/version_info/version_info.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "content/public/test/test_utils.h"
+#include "extensions/features/features.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_service_test_base.h"
 #include "chrome/browser/extensions/extension_util.h"
@@ -365,7 +366,7 @@ TEST_F(SupervisedUserServiceTest, CreatePermissionRequest) {
   }
 }
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 class SupervisedUserServiceExtensionTestBase
     : public extensions::ExtensionServiceTestBase {
  public:
@@ -682,4 +683,4 @@ TEST_F(SupervisedUserServiceExtensionTest, InstallContentPacks) {
   EXPECT_EQ(SupervisedUserURLFilter::ALLOW,
             url_filter->GetFilteringBehaviorForURL(moose_url));
 }
-#endif  // defined(ENABLE_EXTENSIONS)
+#endif  // BUILDFLAG(ENABLE_EXTENSIONS)